Step 2:

Step 3:

Attach the arch to the columns using the corner studs. Attach two 1 x 2 bricks to the 2 x 4 bricks between the columns.

Step 4: Build the Lever.

Attach two 2 x 10 pieces by connecting a one 2 x 6 flat piece to the bottom and one 2 x 8 piece to the top. Attach a rectangle flat piece that is 4 x 6 to the top of the lever. Attach a 1 x 4 block to the last row of the 4 x 6 piece and two 1 x 2 bricks in front. This will hold the object in place before it is catapulted.

Step 5:

Attach a 2 stud slanted piece to hold the object in place before it is catapulted.